更多"In a jerk pump, the amount of fuel "的相关试题:
[单项选择]The plunger in a jerk pump is rotated until the release port is uncoveredIf the port remains uncovered all of the time, which of the listed operations will occur?（）
A. No fuel will be delivered
B. The maximum effective stroke will be attained
C. The fuel delivered to the cylinder will be excessive
D. The injection nozzle will overheat and carbonize
[单项选择]While overhauling a jerk-type fuel pump it is necessary to replace the pump plungerWhich of the parts listed below must also be replaced?（）
A. Delivery check valve
B. Pump barrel
C. Tubing to the injector
D. Cam follower
[单项选择]The amount of fuel injection into a diesel engine cylinder by a unit injector, is controlled by（）
A. the firing pressure in the cylinder
B. a metering helix inside the pump
C. varying the physical length of the plunger stroke
D. varying the clearance between the injector cam and the injector rocker arm
[单项选择]The amount of fuel delivered by a helical plunger fuel injection pump is controlled by （）
A. varying the pump discharge pressure
B. varying the pump return pressure
C. rotation of the pump plunger
D. rotation of the pump barrel
[单项选择]The amount of fuel injected in a particular time, or degree, of crankshaft rotation is termed （）.
A. metering
B. timing
C. rate of injection
D. rate of distribution
[单项选择]The amount of fuel delivered by a unit injector is controlled by the （）
A. camshaft
B. main spring
C. rack position
D. nozzle orifice size
[单项选择]It should be evident that the amount of fuel injected into the cylinder is dependent on the position of the helix relative to the （）.
A. inlet port
B. exhaust port
C. spill port
D. scavenge port
[单项选择]The amount of fuel delivered for each cycle must be in accordance with the engine load, and the same quantity of fuel must be delivered to each cylinder for each power stroke at that load.Which of the following statements describes this requirement?（）
A. Proper timing
B. Accurate metering
C. Suitable injection rate
D. Suitable atomization rate
[单项选择]In a unit injector the amount of fuel that will be forced through the spray nozzle on each stroke of the plunger depends on （）
A. the pump supply pressure
B. the slope of the fuel cam
C. how the plunger is rotated
D. the number of sleeve segments engaged with the rack
[单项选择]The fuel booster pump and steam to fuel heater, together with fuel pipe heater tracer line should be shut off as soon as the （） order is acknowledged.
A. finished with engines
B. stop
C. stand by
D. full ahead
[单项选择]Fuel pump index is （）.
A. the viscosity index
B. the fuel oil contents
C. the starting speed
D. the reading at the rack
[单项选择]If the plunger or barrel of a fuel injection jerk pump becomes damaged,（）
A. only the replacement of the entire pump would be acceptable
B. the injection pump and injection nozzle must be replaced
C. either the barrel or plunger must be replaced
D. the barrel and plunger must be replaced as a unit
[单项选择]Engine fuel pump index is （）.
A. the viscosity index
B. the fuel oil contents
C. the starting speed
D. the reading at the rack
[单项选择]The minimum fuel oil delivery pressure required for diesel engine injection depends primarily on the（）
A. degree of cylinder air turbulence
B. firing pressure in the engine
C. quality of fuel to be injected
D. duration of the ignition delay period
[单项选择]The major cause of fuel pump and injection system problems is （）
A. improper adjustments
B. contaminated fuel
C. kinked fuel lines
D. excessive engine vibration
[单项选择]An increase in the fuel injection pump discharge pressure can be caused by a/an （）
A. leaking delivery valve
B. excessive bearing end play
C. plugged injector spray hole
D. increased plunger stroke
[单项选择]A common trouble with the fuel pump plungers or fuel valve spindle is （）.
A. broken down
B. stuck
C. oil leakage
D. carbonized
[单项选择]A common trouble with the fuel pump plunger or fuel valve spindle is （）.
A. water leakage
B. steam leakage
C. oil leakage
D. air leakage
[单项选择]Movement of the pump control rack in a fuel injection system using individual plunger-type pumps （）
A. changes the position of the fuel inlet ports
B. changes the length of the pump stroke
C. varies the quantity of fuel delivered
D. varies the compression of the delivery valve spring
